On Tue, 15 Feb 2022 at 17:52, <andrey.konovalov@xxxxxxxxx> wrote: > > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > That patch didn't update the case when a stack is retrived from > cached_stacks in alloc_thread_stack_node(). As cached_stacks stores > vm_structs and not stack pointers themselves, the pointer tag needs > to be reset there as well. > > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Marco Elver <elver@xxxxxxxxxx> Did the test catch this? If not, can this be tested? > --- > kernel/fork.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/kernel/fork.c b/kernel/fork.c > index 57d624f05182..5e3ad2e7a756 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -226,15 +226,17 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) > if (!s) > continue; > > - /* Mark stack accessible for KASAN. */ > + /* Reset stack metadata. */ > kasan_unpoison_range(s->addr, THREAD_SIZE); > > + stack = kasan_reset_tag(s->addr); > + > /* Clear stale pointers from reused stack. */ > - memset(s->addr, 0, THREAD_SIZE); > + memset(stack, 0, THREAD_SIZE); > > tsk->stack_vm_area = s; > - tsk->stack = s->addr; > - return s->addr; > + tsk->stack = stack; > + return stack; > } > > /* > -- > 2.25.1 >
